Welding rod



Patented Jan. 12,, 1937 UNITED STATES PATENT OFFICE WELDING ROD Frederick M. Becket,

New York, and- Russell Franks, Jackson Heights, N. Y., 'assignors, by

assignments, to Union Carbide and Carbon Corporation, a corporation of New York No Drawing. Application July 23. 1934, Serial No. 737,380

2 Claims. The invention is an alloy steel welding rod.

Application Serial Number 593,928, filed Feb-, ruary 18, 1932, by Frederick M. Becket and Russell Franks jointly, contains a description of chromibium tend to lose excessive amounts of this constituent when melted by an oxyacetylene torch or an electric arc during welding operations unless 'the material contains an effective amount of silicon. The following table (A) of test data serves to illustrate this fact. The welds in these tests were made in twelve-gage sheet with one-eighth inch temperatures between 300 C. and 850 C. for various lengths of time, a separate sample being used for each combination of temperature and time. After a sample was held at a given temperature for a given length of time it was boiled in an acidified copper sulfate solution in an attempt to disintegrate it by intergranular corrosion.

Table B Analysis Steel N Percent Percent Percent Percent Percent Percent Cr i n b 18.49 8.81 0.85 0.00 1.18 0.18 welding rods, us1ng both the electric arc and the 9 19.45 8. 38 0.57 0.12 1.14 0. 35 oxyacetylene torch methods, employing a suitable j::::::: 121%,? 3'3? 3; 81 i: 31g flux to protect the metal during welding.

Table A Composition of welding rod s g g ggg i Steel Method of No. welding Percent Percent Percent Percent Percent Percent Percent Percent Percent 01' Ni Mn 0 s1 Ch 0 s1 o 1 18.30 8.95 0.54 0.00 0.17 0.72 {gfglff fifigf gfgg 8 8g 2 18.03 9. 27 0. 34 0.11 0. 33 1.21 Electric Arc 0.80 0.32 0.07 3 18.38 8.07 0.03 0.10 0.00 1.15 {$55,533, 53 {33 3 2g 8% Oxyacetylene. 1. 65 0. 78 0. 20 4 18.68 0.27 0.07 0.12 0.91 1.03 {g t 089 M6 xyace y ene .88 l. 24 0.11 18.65 9.10 0.00 0.07 1.37 0.88 g 8 3% 1 Q07 xyace y ene 64 0. l3 0 18.16 8.83 0.03 0.10 1.73 1.04 {g m 1 g; 33 0.09 xyace y one--. 0. 12 7.. 18.35 0.08 0.02 0.00 2.23 1.00 {Electric ARM" 0.93 1,75 M9 Examination of these test results reveals that when the silicon content of the rod was only 0.17%, about 50% of the columbium in the original rod was lost during welding. When the rod contained about 0.7% or more silicon, less than 10% of the columbium in the rod was lost.

We have also found that silicon in substantial amounts tends to improve the resistance of certain chromium-nickel-columbium steels to loss of corrosion resistance on prolonged holding at elevated temperatures. The addition of silicon imparts immunity to intergranular corrosion to many steel compositions which, because of a relatively high carbon content or a somewhat low ratio of columbium to carbon, would otherwise not be completely immune. For example, samples of the steels given in Table B were held at several substantially afiected after they had been held one month at temperatures of 300 0., 400 0., 475 0., 550 0., 650 0., 750 0., and 850 0., and subsequently boiled for 1000 hours.

The present invention is based on the above described discoveries and is an alloy steel welding rod, comprising about 12% to 30% chromium, about 5% to 30% nickel, about 0.01% to 0.3%

about 0.1 to 3% columbium. about 0.7%

to 2%" silicon, and the remainder principally iron. Several per cent. manganese and up to about 4% tantalum may also be present. The columbium content should be about eight to ten times the carbon content. The columbium content preterably exceeds the tantalum content.

The welding rod 0! the invention preferably contains no more than about 2% silicon when the oxyacetylene process is to be used and no more than about 1% silicon when the electric arc process is used.-

The steel welding rod of the invention not only provides filler material which may be deposited by welding without an excessive loss of the valuable and essential constituent, columbium, but also provides material deposited by welding, having improved resistance to corrosion after prolonged holding at elevated temperatures in the neighborhood oi! 500 C.

We claim: 1. A welding rod having substantially the composition: 12% to 30% chromium; 5% to 30% nickel; 0.01% to 0.3% carbon; 0.1% to 3% columbium, the columbium content being at least about eight times the carbon content; 0.7% to 2% silicon;

balance substantially all iron.

2. A welding rod having substantially the composition: 12% to 30% chromium; 5% to 30% nickel; 0.01% to0.3% carbon; 0.1% to3% columbium, the columbium content being at least about ten times the carbon content; 0.7% to 1% silicon;

balance substantially all iron.

FREDERICK M. BECKE'I'. BUSSEIL FRANKS. 

